This research project is directed toward the understanding of the structure and regulation of several mammalian polypeptide hormone genes. Recombinant DNA methods are being used to isolate clones containing sequences for the proteins HCG, ACTH, and insulin. Clones for cDNA have been isolated. Work is in progress to isolate the genes for these same polypeptides using a bacteriophage lambda in vitro packaging system and suitable lambda EK2 vectors (e.g. lambda gt WES.lambdaB and charon 4A). To date, the genes for HGH and rat insulin have been isolated and analysed. The HGH gene seems to have three intervening sequences while the rat insulin gene appears not to have any.